Apparatus for the manufacture of rubber tubing



Jan. 18, 1938. P A, RAlCHE 2,106,018

APPARATUS FOR THE MANUFACTURE OF RUBBER TUBING Original Filed Jan. `250, 1932 Patented Jan. 18, 1938 UNlTEo STATES APPARATUS FOR THE MANUFACTURE OF RUBBER TUBING Paul A. Raiehe, Providence,v R. I., assigner to Davol Rubber Co., a corporation 'of Rhode Island Original application January 30, 1932, Serial No.

589,835, now Patent No. 1,940,145, dated December 19, 1933. Divided and this application November 21, 1933, Serial No. 699,010

9 Claims.

This application is a division of my copending application Ser. No. 589,835 led January 30, 1932; Patent 1,940,145 Dec. 19, 1933, for Method for the manufacture of rubber tubing.

5 My present invention relates to the manufacture of rubber articles, and has particular reference to the manufacture of rubber tubing.

Rubber tubing has hitherto been made from flat stock drawn through an opening in a movable plate, which opening is substantially the outside diameter of the finished tubing, and has comprised a longitudinal seam welded by the use of a welding ux and heat. AThe principal objects of my invention are to utilize an improved apparatus for welding a seam of contiguous edges of rubber by a novel application of'pressure.

The longitudinal seam of commercial rubber tubing forms a structural weakness, on account of the diiculty inproducing perfect'welds com- ;0 mercially, has a tendency to open under pressure, and has hindered the use of rubber tubing for pressure. uids, unlessreinforced by fabric or the like. It is an. additional objectv of my invention to provide an improved construction of g5 rubber tubing that has no longitudinal se'ams,

and that will withstand substantial internal pressure without use of a reinforcing material.

The manufacture .of rubber tubing havingy a Y plurality of layers has heretofore failed to utilize I0. the vfull strength of the rubber layers as supports for each other, because the commercial manufacturel has resulted in layers having parallel grain. A` further object` of my invention is to provide a construction whereby therubber layers :5 will have their grain oneI bias, thus increasing the strength 'of the tubing and providing` a 'maximum support for each layer. With theabove and other objects and advan tag'eous features in view, 'the invention vcomprises l0 a novel, apparatusv forV producing strong, integral rubbertubing, more fully` described inthe ,de, tailed description following, in conjunction with.

the accompanying drawing, and more particularly specified 'in the appended claims.' 5 In the drawing: I

Fig. l'is a fragmentary elevationv ofthe appa` `rat'us for producing the tubing; V y

Ilig. 2 isa side view of. themwelding hammer andthe actuating mechanismv'therefor;

0 Fig. 3 is a `section througharubber tube/formed in accordance with the invention; y

Fig. 4 Ais afragmentary view similar' tov Fig. 1, showing the formation of striped tubing;

Eig. 5 is a. view similar to Fig. 3, but showing an 5 intermediate layer of fabric reinforcement; and

Fig. 6 is an elevation of the carrier roll frame.

Referring to the drawing, the mandrel I0 is rotatably mounted in any suitable manner in a horizontal position, and is actuated through pinion I I by a power gear I2. A carrier roll I3 for 5 rubber is mounted for rotary movement on la shaft I4 which is held in a standard .I5 swivelly mounted o n a base I6.

The carrier roll contains a roll of rubber ribbon I1, which is spirally wound on the mandrel as 10 the roll and the mandrel rotate. The contigu-` ous Aseams formed by the edges of the ribbons are subjected to the hammering action of a rapidly oscillating hammer I8, which is supported on anarm I9 pivotally mounted as at 20. The arm is spring pressed upwardly. by a tension spring I9a to bring the hammer against the seam, and the hammer is periodically positively swung into hammering position `against the tension of the spring bya toothed actuating wheel 2l winch is splined on a rotatable shaft 22. Preferably, the mandrel is splined in its pinion,` and is shifted longitudinally by any desired mechanismy of4 usual type, as by a flyer 23 engaging a ange 2ten the mandrel and threaded-on' a screw 25, so as to always bring the seam formed by the contiguous edges of the ribbon over the hammer head;v but it is a matter of mechanical expediency, if desired, to shift the carrierjroll v and the hammering mechanism, instead of the 30 mandrel. f

As shown in Figs. land 4, the shaft III is securely held vinthe spaced bearings 26, 2l of the bearing yoke 28, which is mounted on the center 1 post 29 of the standard I5. 'The carrier roll. I3 35 is mounted on the end of the shaft AI4 against a spring 30, which is thus pressed against aliangel 3I fixed on the shaft I4 at one end, and lresiliently holds'the carrier roll againstthe retaining nut 32 von the threadedend of the shaf'tto exert'40 a slight, controlled resistance to turning of the, carrier roll. kThe swivel 'movement is for the purposey of Acontrolling the angle of feed of the'I rubber ribbon. l l l r y It has been lfound theta moderate recprocas' tionof the hammer'under a moderatespri'ng"A pressure'is sufficient to produce a vperfect vweld n withoutuse of abonding-agent; it may be de- 'sirable,` however,` to also utilize rubber bonding.;Y material orcement between thecontiguous edges of 'the `seam, inv order to ensure success of the l` weld. Theformed tubing is `nishedby treat-v .f ing and curing in the usual manner. If. a multilayer .tubing is desired, the manufacture is easily accomplished by reversing the f mandrel rotation, thus forming each layer with its welded seams across the welded seam of the preceding layer as indicated at 33, 34 in Fig. 3; the construction is therefore extremely strong and able to withstand substantial pressure.

'I'he labove described welding method is particularly applicable for the manufacture of striped tubing, as indicated in Fig. 4. The large rubber ribbon 35 and the small 'rubber ribbon 36 are of different colors, and the resulting tubing is a homogeneous tubing having an easily distinguished spiral stripe.

When the tubing is to be used for quite high pressure fluids, a fabric layer 31 may beutilized,

as indicated in Fig. 5, as a reinforcing material' particularly when a laminated construction is to be formed of sheets which have dierent grain direction.

The use of layers of different grain direction is very eifectivein the case of tubing, as the resulting tubing is easily and inexpensively manufactured, is very strong, is homogeneous, and is very resistant to internal pressure.

While I have described a specic apparatus for producing the improved tubing, it is obvious that such changes in the arrangement and size of the parts, and in the arrangement, the character, and the material of the tubing layers, may be made as appear desirable, within the spirit and the scope of the appended claims.

I claim:`

1. In a machine for forming rubber tubes, a rotatable mandrel, a rotatable carrier roll shaft mounted adjacent to said mandrel and adapted to carry a spool of strip rubber,'mechanlsm for rotating said mandrel.'a reciprocable hammer mounted adjacent said mandrel for hammering the seams of the strip rubber afterY it vis wound on said mandrel. and mechanism for relatively shifting the mandrel and hammer longitudinally along the axis of said mandrel.

2. In a machine for forming rubber tubes, a rotatable mandrel, a rotatable carrier roll shaft mountedadjacent to said mandrel and adapted to carry a spool of strip4 rubber, 4mechanism for rotating said mandrel, a reciprocable, hammer mounted adjacent said mandrel. said hammer being adapted to engage the seams of strip rubber on the rotating mandrel and mechanism for shifting said mandrel axially.

3. In a machine for forming rubber tubes. a rotatable mandrel, a rotatable carrier roll shaft mounted adjacent to said mandrel and adapted to carry a spool of strip rubber, mechanism for for'intermittently forcing said head away from said seams of ystrip rubber on ,s 4. In a machine for forming rubber tubes, a rotatable mandrel, a rotatable carrier roll shaft mounted adjacent to said mandrel and adapted to carry a spool of strip rubber, said carrier roll shaft being adjustable to a predetermined angular relation with respect to said mandrel,

mechanism for rotating said mandrel, and a reciprocable hammer mounted adjacent said mandrel, said hammer being adapted to engage the seams of strip rubber on the rotating mandrel.

5. In a machine for forming rubber tubes, a rotatable mandrel, a rotatable carrier roll shaft mounted adjacent to said mandrel and adapted to carry a spool of strip rubber, said carrier roll shaft being adjustable to a predetermined angular relation with respect to said mandrel, mechanism for rotating said mandrel, a reciprocable hammer mounted adjacent said mandrel, said hammer being adapted to engage the seams of strip rubber onthe rotating mandrel and mechanism for shifting said mandrel axially.

6. In a machine for forming rubber tubcsa rotatable mandrel, a rotatable carrier roll shaft mounted adjacent to said mandrel and adapted to carry a spool of strip rubber, said carrier roll shaft being adjustable to a predetermined angular relation with respect to said mandrel,

mechanism for rotating said mandrel, a hammer device comprising a rod and a head, the rod being pivotally mounted to position the hammer vhead adjacent said mandrel, a spring engaging said rod to force said head towards said mandrel, said hammer being adapted to engage the seams of strip rubber on the rotating mandrel and mechanism for intermittently forcing said head away from said mandrel.

7. In a machine for forming rubber tubes, a rotatable mandrel, a rotatable carrier roll shaft mounted adjacent to said mandrel, a carrier roll for strip rubber rotatably mounted on said shaft, means for tensioning the rotation of said carrierroll, mechanism for rotating said mandrel, and a reciprocable hammer mounted adjacent said mandrel, said hammer being adapted to engage the seams of strip rubber on the rotating mandrel.

8. In a machine for forming rubber tubes, a

`rotatable mandrel, a rotatable carrier roll shaft mounted adjacent to said mandrel, a carrier roll -for strip rubber rotatably mounted on said shaft,

means for tensioning the rotation of said carrier roll, mechanism for rotating said mandrel, a

reciprocable hammer mounted adjacent said mandrel, said hammer being adapted to engage the seams of strip rubber on the rotating mandrel'and mechanism for shifting said mandrel axially.

9. In a machine for forming rubber tubes, a

rotatable mandrel, a rotatable carrier vroll shaft drel, a hammer device comprising a rod and a head, the rod being pivotally mounted to position the hammer head adjacent said mandrel, a spring engaging said rod to force said head towards, sifmandrel, and mechanism for intermittently forcing said head away from said mandrel, said hammer being adapted to engage the the rotating mandrel.

PAUL A. RAICHI. 

